[core/input] Invoke commands in a subshell

add shell capability to util.cli and make sure that the input module
uses that to reliably spawn whatever command the user wants to run.

see #628

bumblebee_status/core/input.py

@@ -38,7 +38,7 @@ def __event_id(obj_id, button):
 
 def __execute(cmd):
     try:
-        util.cli.execute(cmd, wait=False)
+        util.cli.execute(cmd, wait=False, shell=True)
     except Exception as e:
         logging.error("failed to invoke callback: {}".format(e))
 

bumblebee_status/util/cli.py

@@ -11,6 +11,7 @@ def execute(
     include_stderr=False,
     env=None,
     return_exitcode=False,
+    shell=False,
 ):
     """Executes a commandline utility and returns its output
 
@@ -20,13 +21,14 @@ def execute(
     :param include_stderr: set to True to include stderr output in the return value, defaults to False
     :param env: provide a dict here to specify a custom execution environment, defaults to None
     :param return_exitcode: set to True to return a pair, where the first member is the exit code and the message the second, defaults to False
+    :param shell: set to True to run command in a separate shell, defaults to False
 
     :raises RuntimeError: the command either didn't exist or didn't exit cleanly, and ignore_errors was set to False
 
     :return: output of cmd, or stderr, if ignore_errors is True and the command failed; or a tuple of exitcode and the previous, if return_exitcode is set to True
     :rtype: string or tuple (if return_exitcode is set to True)
     """
-    args = shlex.split(cmd)
+    args = cmd if shell else shlex.split(cmd)
     logging.debug(cmd)
     try:
         proc = subprocess.Popen(
@@ -34,6 +36,7 @@ def execute(
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT if include_stderr else subprocess.PIPE,
             env=env,
+            shell=shell,
         )
     except FileNotFoundError as e:
         raise RuntimeError("{} not found".format(cmd))

tests/core/test_input.py

@@ -70,7 +70,9 @@ class config(unittest.TestCase):
                 self.inputObject, self.someEvent["button"], self.someCommand
             )
             core.input.trigger(self.someEvent)
-            cli.execute.assert_called_once_with(self.someCommand, wait=False)
+            cli.execute.assert_called_once_with(
+                self.someCommand, wait=False, shell=True
+            )
 
     def test_non_existent_callback(self):
         with unittest.mock.patch("core.input.util.cli") as cli: